The climate in a convertible depends greatly on whether the top is up or down. For this reason, the climate-control system on the IS Convertible is designed to monitor not just the interior temperature, but the exterior temperature and position of the sun as well. All the while, airflow and temperature settings are constantly adjusted. And when the top is down, the system even takes into account the vehicle's speed. This all helps ensure the ideal interior temperature, whether the top is up or down.